1. Field of the Invention
The present invention is related to a shock absorption device of a running apparatus and particularly to a shock absorption device, which is provided with a shock absorbing elastic member at the rear side of a running apparatus to protect the knees of the user from injury.
2. Brief Description of the Related Art
The running apparatus has become one of basic fittings for indoor sports nowadays but there is deficiency in the currently used running apparatus. Due to the moving human body being incompatible for high speed operation of the running apparatus, it often occurs the ankles and the knees being hurt. It is known that the body moves and the ground is stationary during a person running for taking exercise on the ground and the body can move forward after the feet touching the ground and keeping the body being in a steady state. However, the foot pedal of the running apparatus keeps moving while the runner keeps moving on the foot pedal during running and the runner has to adjust movements of the ankles and the knees to comply with moving speed of the foot pedal in a way of the upper part of the body keeping unmoving. Hence, it is very easy for the ankles and the knees to get hurt during the feet trying to keep the body in a state of balance and to support the body weight. In addition, the foot pedal is made of hard metal and once the feet contact the foot pedal, injury at the ankles and knees becomes more serious due to acceleration of gravity exerted by the body.
Referring to FIG. 1, one of the conventional running apparatus is illustrated to add with a cushion design for decreasing burden of foot joints and knee joints against the acceleration of gravity in order to overcome the preceding deficiency of the ankles and the knees being easily getting hurt. The running apparatus 10 provides a foot pedal 11 is fixedly attached to the a lifted base 14 and an elevation device 12 is disposed at the front side of the lifted base 14 with a fulcrum roller 13 at the rear side of the lifted base 14. When the elevation device 12 moves upward and downward, the fulcrum roller 13 acts as a fixed rotational shaft during the foot pedal 11 forming an inclining position or a horizontal position.
The running apparatus disclosed in Taiwanese Patent Application Nos. 92204569 and 91221543 are provided with a suspension component and a cushion member in the elevation device 12 of the preceding conventional running apparatus to offset the acceleration of gravity generated by the body weight by way of elasticity during the user running on the foot pedal so as to protect the ankles and the knees. However, the revised elevation device 12 has affected the whole structure of the running apparatus and has to change relative motion between the elevation device 12 and rest parts in the running apparatus. Hence, it adds difficulty to make a change and high fabrication cost of the running apparatus.
Referring to FIGS. 2 and 3, a recently improved running apparatus provides a soft pad 15, which is disposed under the lifted base 14, to be supported with a circular member 16 therein for strengthen the soft pad 15. The circular member 16 has a screw 17 at the center thereof for fastening the bottom of the running apparatus. A joining surface 18 between the circular member 16 and the lifted base 14 should not be covered with the soft pad 15, otherwise, it is hard to obtain a required tightness between the circular member 16 and the lifted base 14. Thus, the preceding arrangement has the following shortcomings:
1. It is not possible for the exposed soft pad to be fixedly attached to the bottom of running apparatus with a tool such that it results in unfavorable steadiness of the running apparatus.
2. The soft pad is damaged easily under being subjected a force such that it has to face a risk of loosening. If a tool is used for fixing the soft pad, it is easy to break the soft pad.
3. The soft pad provides a thickness only enough for decreasing noise resulting from impact and reducing the sound decibel.
4. The soft pad easily detaches from the circular member under a force in case of the joining surface being covered with the soft pad in addition to improper engagement.